I have the values Y1 and X1 (where X1 is always bigger than Y1). If I want to draw a curve between the two points y1, x1 based on a circle (no ellipse), how to find out the y2 value which would be the center of the cycle and the radius (r)? I think the circle's radius would get bigger and it's center would move...You know the equation of a circle has the form $$ r^2=(x-a)^2+(y-b)^2. $$ If you have the equation in this form, you can read off the center and radius. But you don't have that. You need to do a bit of work to get what you have into the form you want. The tool to use here is: Completing the Square.Find the radius of the below circle Equation of the circle with centre and radius is.The general form of the equation for a circle with its center at (h, k) and radius of r is: Let's get your equation into this form, then we can find the center (h, k) and the radius Complete the square to get: x^2+6x+9 + y^2 = -8+9 Factor to get: (x+3)^2 + (y-0)^2 = 1 Center at (-3,0) Radius = 1 Cheers, Stan H.Circle Equation Tutorial, Circle equations, Standard Form equations, General Form equations. Figure 1 below shows a circle whose center is at point (4, 3) with a radius of 2. How do we find the standard form equation of this circle?
algebra precalculus - Finding the center and radius of a circle given...
Start studying Equation of a Circle. Learn vocabulary, terms and more with flashcards, games and other study tools. What is the radius of a circle whose equation is x2 + y2 + 8x - 6y + 21 = 0?Let us put a circle of radius 5 on a graph: Now let's work out exactly where all the points are. We make a right-angled triangle It is a circle equation, but "in disguise"! So when you see something like that think "hmm that might be a circle!" In fact we can write it in "General Form" by putting constants...This video provides a little background information and three examples of how to find the center and radius of a circle, given an equation. These problems...8 time by 2 = 16 which is the diameter of the circle. 1 decade ago. The radius of this circle is 8, so its circumference is 16π. Source(s): I have taught math for over 40 yr.
Solved: What is the radius of the circle with equation... | Chegg.com
Explanation: Equation of a circle is x^2+y^2=r^2 r^2=9 r=3. Benito has a bamboo stick measuring 70 cm long.he cuts it into 3 pieces.the first half the length of the second piece,which is the longest?.if the lon … gest piece is 28.4 cm,how long is each of the other two pieces?...with radius 5 whose centre lies on x-axis and passes through the point (2, 3). We know that equation of circle is (x - h)2 + (y - k)2 = r2 Centre of circle is denoted by (h, k) Since it (h, 0) & given Radius = 5 Distance between centre and point on circle = radius Distance between points (h, 0) & (2,3) = 5...The equation of a circle in the xy-plane is shown above. What is the radius of the circle?Find the equation of a circle whose center is at the point (-2 , 3) and its diameter has a length of 10. Question 3. Find an equation of the circle that is is tangent to both the x and y axes, with a radius of 4 and whose center is located in the second quadrant.A circle can be defined as the locus of all points that satisfy an equation derived from the Pythagorean Theorem. When we see the equation of a circle such as. we know it is a circle of radius 9 with its center at x = 3, y = -2. The radius is 9 because the formula has r2 on the right side.
A circle is simple to make:
(*42*)Draw a curve that is "radius" awayfrom a central point.And so:
(*42*)All points are the same distancefrom the heart.In fact the definition of a circle is
Circle on a Graph
Let us put a circle of radius 5 on a graph:
(*42*)Now let's figure out exactly where all the issues are.
We make a right-angled triangle:
(*42*)And then use Pythagoras:
(*42*)x2 + y2 = 52 (*42*)There are a vast quantity of those issues, listed below are some examples: (*42*) x y x2 + y2 5 0 52 + 02 = 25 + 0 = 25 3 4 32 + 42 = 9 + 16 = 25 0 5 02 + 52 = 0 + 25 = 25 −4 −3 (−4)2 + (−3)2 = 16 + 9 = 25 0 −5 02 + (−5)2 = 0 + 25 = 25 (*42*)In all instances a point on the circle follows the rule x2 + y2 = radius2We can use that idea to find a lacking value
Example: x price of 2, and a radius of 5Start with:x2 + y2 = r2
Values we know:22 + y2 = 52
Rearrange: y2 = 52 − 22
Square root all sides: y = ±√(52 − 22)
Solve:y = ±√21
y ≈ ±4.58...
(The ± manner there are two possible values: one with + the different with −)
And listed here are the two points:
(*42*)More General Case
Now let us put the center at (a,b)
(*42*)So the circle is all the issues (x,y) which might be "r" clear of the center (a,b).
Now shall we work out the place the points are (the usage of a right-angled triangle and Pythagoras):
(*42*)It is the similar concept as ahead of, but we need to subtract a and b:
(*42*)(x−a)2 + (y−b)2 = r2 (*42*)And that is the "Standard Form" for the equation of a circle!It presentations all the necessary knowledge at a glance: the middle (a,b) and the radius r.
Example: A circle with heart at (3,4) and a radius of 6:Start with:
(x−a)2 + (y−b)2 = r2
Put in (a,b) and r:
(x−3)2 + (y−4)2 = 62
We can then use our algebra talents to simplify and rearrange that equation, depending on what we want it for.
Try it Yourself
"General Form"
But you may see a circle equation and now not comprehend it!
(*42*)Because it may not be in the neat "Standard Form" above.As an instance, let us put some values to a, b and r and then amplify it
Start with:(x−a)2 + (y−b)2 = r2
Example: a=1, b=2, r=3:(x−1)2 + (y−2)2 = 32
Expand: x2 − 2x + 1 + y2 − 4y + 4 = 9
Gather like terms:x2 + y2 − 2x − 4y + 1 + 4 − 9 = 0And we finally end up with this:
(*42*)x2 + y2 − 2x − 4y − 4 = 0 (*42*)It is a circle equation, but "in disguise"!So while you see something like that assume "hmm ... that might be a circle!"
In truth we will be able to write it in "General Form" by means of hanging constants instead of the numbers:
(*42*)x2 + y2 + Ax + By + C = 0Note: General Form always has x2 + y2 for the first two phrases.
Going From General Form to Standard Form
Now believe we now have an equation in General Form:
(*42*)x2 + y2 + Ax + By + C = 0How can we get it into Standard Form like this?
(*42*)(x−a)2 + (y−b)2 = r2The solution is to Complete the Square (read about that) two times ... once for x and as soon as for y:
Example: x2 + y2 − 2x − 4y − 4 = 0Start with:x2 + y2 − 2x − 4y − 4 = 0
Put xs and ys together:(x2 − 2x) + (y2 − 4y) − 4 = 0
Constant on right:(x2 − 2x) + (y2 − 4y) = 4
Now complete the sq. for x (take half of the −2, square it, and upload to all sides):
(*42*)(x2 − 2x + (−1)2) + (y2 − 4y) = 4 + (−1)2And whole the square for y (take part of the −4, square it, and add to both sides):
(*42*)(x2 − 2x + (−1)2) + (y2 − 4y + (−2)2) = 4 + (−1)2 + (−2)2Tidy up:
Simplify:(x2 − 2x + 1) + (y2 − 4y + 4) = 9
Finally:(x − 1)2 + (y − 2)2 = 32
And we've got it in Standard Form!
(Note: this used the a=1, b=2, r=3 instance from sooner than, so we got it correct!)
Unit Circle
If we place the circle heart at (0,0) and set the radius to 1 we get:
(*42*)(x−a)2 + (y−b)2 = r2 (*42*)(x−0)2 + (y−0)2 = 12 (*42*)x2 + y2 = 1 Which is the equation of the Unit CircleHow to Plot a Circle by means of Hand
1. Plot the middle (a,b)
2. Plot 4 issues "radius" clear of the heart in the up, down, left and correct course
3. Sketch it in!
Example: Plot (x−4)2 + (y−2)2 = 25The formula for a circle is (x−a)2 + (y−b)2 = r2
So the heart is at (4,2)
And r2 is 25, so the radius is √25 = 5
So we will be able to plot:
The Center: (4,2) Up: (4,2+5) = (4,7) Down: (4,2−5) = (4,−3) Left: (4−5,2) = (−1,2) Right: (4+5,2) = (9,2)Now, simply sketch in the circle the easiest we will be able to!
How to Plot a Circle on the Computer
We need to rearrange the components so we get "y=".
We should finally end up with two equations (most sensible and backside of circle) that can then be plotted.
Example: Plot (x−4)2 + (y−2)2 = 25So the heart is at (4,2), and the radius is √25 = 5
Rearrange to get "y=":
Start with: (x−4)2 + (y−2)2 = 25
Move (x−4)2 to the right: (y−2)2 = 25 − (x−4)2
Take the square root: (y−2) = ± √[25 − (x−4)2]
(understand the ± "plus/minus" ...there will also be two sq. roots!)
Move the "−2" to the right:y = 2 ± √[25 − (x−4)2]
So when we plot these two equations we must have a circle:
y = 2 + √[25 − (x−4)2] y = 2 − √[25 − (x−4)2]Try plotting those purposes on the Function Grapher.
It is additionally conceivable to make use of the Equation Grapher to do it multi functional pass.
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